#robotics Logs
May 22 2020
#robotics Calendar
01:50 AM rue_bed: Samian, really?
10:46 AM deshipu: the laser-cut body fits together pretty well: https://cdn.mastodon.technology/media_attachments/files/006/745/786/original/9aebf2419127dc11.jpeg
10:50 AM veverak: nice
06:22 PM Tom_itx is now known as Tom_L
08:43 PM ferdna: i am building a cnc... i am having problems choosing a power supply...
08:43 PM ferdna: https://www.ebay.com/itm/FREE-fast-Wantai-1PC-Nema34-Stepper-Motor-1232oz-in-118-MM-14MM-SHAFT/323200909703
08:43 PM ferdna: those are the motors
09:00 PM rue_bed: I'm building a cnc too!
09:00 PM rue_bed: I'm using DC motors and biulding servo controllers
09:01 PM rue_bed: 5.6A coils you have, wow
09:02 PM rue_bed: ferdna,
09:02 PM rue_bed: your power supply needs wattage, not amps
09:02 PM rue_bed: so, lets say you use a 24V supply
09:03 PM rue_bed: each of your motor coils is 5.6A * 3V = 16.8w
09:03 PM rue_bed: you have two coils per motor
09:03 PM rue_bed: so each motor needs 34w
09:04 PM rue_bed: at 24V, 34w is 1.4A
09:04 PM rue_bed: so, if you provide 24V, 2A per motor, your ok
09:09 PM ferdna: rue_bed, i got a 48V power supply
09:10 PM Tom_L: how many amps?
09:10 PM ferdna: 31.3A
09:10 PM ferdna: Tom_L,
09:11 PM ferdna: ...
09:11 PM Tom_L: that's alot
09:11 PM ferdna: do i need to match the voltage to my power supply and motors?
09:11 PM ferdna: if my motors take 3.6V... my power supply has to be 3.6 as well?
09:11 PM ferdna: in other words... can i use a 48V with those motors?
09:12 PM Tom_L: with a chopper driver yes
09:12 PM Tom_L: my supply is 48v
09:12 PM Tom_L: i would have gone higher but that's what i had
09:12 PM rue_bed: ferdna,
09:12 PM ferdna: Tom_L, i have geckos
09:12 PM rue_bed: read what I said
09:12 PM ferdna: yes rue_bed ?
09:13 PM ferdna: ohhh... i did..
09:13 PM ferdna: however... i need basic words
09:13 PM ferdna: and i have stupid questions to ask
09:13 PM rue_bed: then, for 48V how many amps do you neeed?
09:13 PM ferdna: my motors are 5.6A
09:13 PM rue_bed: no
09:13 PM ferdna: i have 3 of them
09:13 PM rue_bed: no
09:13 PM rue_bed: no
09:13 PM rue_bed: no
09:13 PM rue_bed: I said you have to match watts
09:14 PM rue_bed: your motors take 34w
09:14 PM ferdna: i am lost at that
09:14 PM rue_bed: the drivers convert
09:14 PM ferdna: ohh the geckos convert it then
09:14 PM rue_bed: because you use constant current drivers
09:14 PM ferdna: ohhh
09:14 PM rue_bed: so, for 48V, you need 1A per motor
09:15 PM rue_bed: because the watts need to match, not the current
09:15 PM ferdna: ohhhh
09:16 PM ferdna: this is the one:
09:16 PM ferdna: https://www.alliedelec.com/product/mean-well-usa/se-1500-48/70230351/
09:16 PM rue_bed: how many motors will you be using?
09:16 PM rue_bed: 3? 4? 5?
09:16 PM ferdna: 4
09:17 PM rue_bed: my machine will be using 4
09:17 PM rue_bed: ok, you need 4A from your 48V supply
09:17 PM Tom_L: wow
09:17 PM ferdna: Tom_L, wow?
09:17 PM Tom_L: so one of my 3 transformers would be sufficient for mine
09:17 PM Tom_L: :)
09:17 PM rue_bed: Tom_L, measure your draw
09:17 PM rue_bed: after your caps
09:18 PM Tom_L: iirc they're good for 6A ea
09:19 PM Tom_L: i've considered doing that in the past but just never have
09:19 PM ferdna: so i can use that power supply then....
09:22 PM ferdna: rue_bed, Tom_L: https://imgur.com/gxarkE0
09:32 PM rue_bed: looks good
09:33 PM rue_bed: maybe, is that a mach3 board?
09:33 PM rue_bed: ferdna,
09:34 PM rue_bed: Tom_L, is he at $1000 yet?
09:34 PM rue_bed: I dont think I'v hit $20 on mine yet
09:34 PM ferdna: rue_bed, its a parallel board...
09:35 PM ferdna: i will be using linuxcnc
09:35 PM rue_bed: ferdna, you will get frustrated at the speed limit of the parallel board
09:35 PM rue_bed: Tom_L, tell what your using
09:35 PM Tom_L: what/
09:35 PM Tom_L: ?
09:36 PM rue_bed: Tom_L, uses linuxcnc
09:36 PM ferdna: ohh recommend a cnc controller then
09:36 PM Tom_L: the mesa cards?
09:36 PM rue_bed: Tom_L, yea
09:36 PM Tom_L: what interface?
09:36 PM rue_bed: not parallel
09:36 PM Tom_L: epp eth spi ...
09:36 PM Tom_L: pci pcie
09:36 PM rue_bed: not parallel
09:36 PM Tom_L: parallel is fine
09:36 PM rue_bed: slow
09:36 PM Tom_L: i'm using parallel to my mesa card
09:36 PM Tom_L: not slow
09:36 PM ferdna: which one are you using Tom_L ?
09:37 PM rue_bed: I'm talking about step/dir parallel port like ferdna has there
09:37 PM Tom_L: i have several but am using the 7i90 on my parallel port
09:37 PM Tom_L: the eth equivalent is a 7i80
09:37 PM rue_bed: Toms card does the steps
09:37 PM Tom_L: you will need an isolation board of some kind
09:38 PM Tom_L: he's got some now that have drivers on the card
09:38 PM rue_bed: I should go work on my motor drivers
09:38 PM Tom_L: dunno the part numbers
09:38 PM Tom_L: rue_bed, you should be rue_shop1
09:38 PM rue_bed: collapsed when I got home
09:39 PM rue_bed: I'm just about up, waiting for the double vision to go away
09:39 PM Tom_L: did you see the rpi controlling the mill?
09:39 PM rue_bed: yes
09:39 PM Tom_L: i didn't notice any difference really
09:39 PM rue_bed: whats the interface between the pi/drivers?
09:39 PM Tom_L: i have 2 but that one was ethernet
09:40 PM Tom_L: i also tested spi
09:40 PM rue_bed: interesting
09:40 PM ferdna: i couldnt find it
09:40 PM ferdna: https://store.mesanet.com/index.php?route=product/category&path=83
09:40 PM Tom_L: find what?
09:40 PM ferdna: your card online
09:40 PM Tom_L: http://store.mesanet.com/index.php?route=product/product&product_id=291&search=7i90
09:41 PM rue_bed: ferdna, if you start with that card you have, you can get the machine working and understand the speed limit caused by your parallel port
09:41 PM Tom_L: the daughter card i'm using is a 7i47s
09:41 PM Tom_L: the 's' adds analog spindle control
09:41 PM ferdna: rue_bed, i rather not...
09:42 PM Tom_L: there are smaller cards if you don't need that much
09:42 PM rue_bed: Tom_L, has a good system, its too expensive for me tho :)
09:42 PM rue_bed: I use GRBL
09:42 PM Tom_L: http://store.mesanet.com/index.php?route=product/product&product_id=302&search=7i92
09:42 PM Tom_L: ethernet interface
09:42 PM rue_bed: but my new machine is really big and I'm not sure how it will perform
09:42 PM ferdna: whats your view on ... acorn and smooth?
09:42 PM Tom_L: 34? io
09:43 PM Tom_L: squirrels eat acorns
09:43 PM ferdna: hehehe
09:43 PM Tom_L: other than that it means nothing to me
09:43 PM rue_bed: ferdna, how big will your machine be?
09:43 PM Tom_L: aparently pretty big if he's using nema34
09:44 PM ferdna: its a grizzly... i am converting it...
09:44 PM ferdna: rue_bed, ^
09:44 PM rue_mohr: ahh, nice
09:44 PM Tom_L: you probably don't need that big of stepper
09:45 PM ferdna: yeah... i heard i could use something smaller... but... future proof... spend once cry once...
09:45 PM Tom_L: https://www.ebay.com/itm/3pcs-NEMA23-570OZ-IN-5A-3-8-DUAL-SHAFT-STEPPER-MOTOR/253223632606?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
09:45 PM Tom_L: i'm using those
09:45 PM Tom_L: i've never stalled them
09:46 PM Tom_L: i did get the table close to the table vise and it just moved the cnc
09:46 PM ferdna: ohh nice... and they are cheap
09:46 PM Tom_L: and i'm only running those at 2.5A instead of the 5A they can handle
09:47 PM ferdna: what else will i be using??
09:48 PM ferdna: so powersupply connect it directly to the geckos
09:48 PM ferdna: and then from geckos to motors...
09:48 PM Tom_L: what gecko?
09:48 PM Tom_L: i'm using the 203v
09:49 PM Tom_L: https://www.youtube.com/watch?v=VUDHCXu4Pwo
09:49 PM Tom_L: i can take a pretty decent cut
09:51 PM ferdna: geckos 215
09:52 PM ferdna: it looks nice!
09:52 PM ferdna: ...
09:52 PM ferdna: so you recommend going the rpi4 instead of a full blown machine?
09:53 PM ferdna: you need to organize that wiring... https://youtu.be/g0OLIth_cOI?t=16
09:58 PM Tom_L: that _is_ organized!!
09:58 PM ferdna: Tom_L, ^
09:58 PM ferdna: hahaha
09:58 PM Tom_L: it runs like a top
09:59 PM Tom_L: the rpi4 is a viable contender yes but you can't do much else on it while you run the mill
09:59 PM Tom_L: that i did purely for a test
09:59 PM ferdna: what image are you using?
09:59 PM Tom_L: an arm variant of buster
09:59 PM Tom_L: debian 10
10:00 PM Tom_L: it's still being tested
10:00 PM Tom_L: i think
10:01 PM ferdna: ohhh cool
10:01 PM Tom_L: the pc i normally use on the mill is an old intel D525 mb running wheezy
10:01 PM Tom_L: i've only had the pi about a week
10:02 PM ferdna: ohhh
10:02 PM Tom_L: the pi runs about 51c with that heatsink and no fan
10:03 PM Tom_L: mesa has a daughter card for the rpi also
10:04 PM Tom_L: http://store.mesanet.com/index.php?route=product/product&product_id=338&search=7c81
10:04 PM Tom_L: http://store.mesanet.com/index.php?route=product/product&product_id=345&search=7c80
10:04 PM Tom_L: 2 actually
10:05 PM Tom_L: just depends what you need
10:05 PM Tom_L: the pi mounts to the bottom and you put a ribbon between i think
10:06 PM Tom_L: for spi interface
10:06 PM ferdna: ohhh
10:07 PM Tom_L: he also has standard 26pin headers for his daughter cards
10:07 PM Tom_L: for whatever you need
10:08 PM Tom_L: it really depends what interface you have or want to use
10:08 PM Tom_L: he has cards for spi, ethernet, epp, pci, pcie
10:09 PM Tom_L: and they're either a 26 pin header or 40 depending on the series of cards
10:09 PM ferdna: so what controller should i get?
10:09 PM ferdna: mesa looks old
10:10 PM Tom_L: https://mesaus.com/
10:10 PM Tom_L: same cards but may be layed out a little easier to understand
10:10 PM Tom_L: he's a mesa distributor
10:10 PM Tom_L: mesa is the primary cards used for linuxcnc
10:11 PM ferdna: Tom_L, ok ok.. you convinced me...
10:12 PM ferdna: what should i get?
10:12 PM Tom_L: i can't make that choice
10:12 PM Tom_L: what pc?
10:12 PM Tom_L: what interface?
10:12 PM Tom_L: ask on their channel and you'll get some good input
10:13 PM ferdna: should i got the rpi4 route?
10:13 PM ferdna: go*
10:13 PM Tom_L: it's still somewhat experimental
10:13 PM Tom_L: several are going that route
10:14 PM Tom_L: if you do, i recomend this: https://www.amazon.com/gp/product/B07XTQL6YZ/
10:14 PM Tom_L: https://www.amazon.com/Metal-Raspberry-Heatsink-Thermal-Adhesive/dp/B07VMD25SK
10:14 PM Tom_L: and that
10:15 PM Tom_L: the kit gets you a decent supply with a switch and a micro hdmi to hdmi cable
10:16 PM Tom_L: i ordered a micro to vga adapter afterwards for an older monitor that didn't support hdmi
10:17 PM ferdna: that looks good
10:18 PM Tom_L: https://www.amazon.com/Anbear-Female-Converter-Adapter-Plated/dp/B074SD9RTF/ref=sr_1_4?dchild=1&keywords=micro+hdmi+to+vga&qid=1590203337&s=electronics&sr=1-4
10:24 PM ferdna: i am dumping the rpi4 idea
10:24 PM ferdna: Tom_L, i will go with a pcie interface
10:34 PM ferdna: Tom_L, https://mesaus.com/product/6i25-7i76-kit/
10:34 PM ferdna: that one?
10:36 PM Tom_L: that would be a good one
10:37 PM Tom_L: before you do anything decide what pc you are going to use and run a latency test on it with the linuxcnc live cdd
10:37 PM Tom_L: -d
10:38 PM Tom_L: you can tweak the bios to get a little better performance if needed usually
10:38 PM ferdna: ohh
10:38 PM Tom_L: turn off hyperthreading etc
10:39 PM ferdna: really? i thought hyperthreading was good
10:39 PM Tom_L: not for realtime
10:39 PM ferdna: ohhh
10:44 PM Tom_L: what sort of control box are you going to use?
10:45 PM ferdna: Tom_L, what do you mean?
10:45 PM ferdna: like the enclosure?
10:45 PM Tom_L: yes
10:45 PM ferdna: i bought this one... https://www.amazon.com/gp/product/B07MXQ6B4C/
10:46 PM Tom_L: nice one
10:46 PM ferdna: yeah
10:46 PM Tom_L: hope it's big enough
10:46 PM ferdna: i dont know how i will lay everything out
10:47 PM ferdna: Tom_L, one more question... i am planning on using neutrik connectors instead of aviation connectors
10:47 PM Tom_L: dunno what those are
10:49 PM ferdna: https://s.yimg.com/aah/pchcables/neutrik-connectors-7.png
10:49 PM Tom_L: to give you an idea, this is the size of my enclosure: https://www.ebay.com/itm/Rittal-AX-1360-000-Quadro-elettrico-600-x-600-x-350-Lamiera-dacciaio-Gri-1360000/124156503281?hash=item1ce84de4f1:g:JHwAAOSwqmVemO4x
10:50 PM ferdna: ohh pretty close in size